scholarly journals Use of Cement Suspension as an Alternative Matrix Material for Textile-Reinforced Concrete

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2127
Author(s):  
Richard Fürst ◽  
Eliška Fürst ◽  
Tomáš Vlach ◽  
Jakub Řepka ◽  
Marek Pokorný ◽  
...  

Textile-reinforced concrete (TRC) is a material consisting of high-performance concrete (HPC) and tensile reinforcement comprised of carbon roving with epoxy resin matrix. However, the problem of low epoxy resin resistance at higher temperatures persists. In this work, an alternative to the epoxy resin matrix, a non-combustible cement suspension (cement milk) which has proven stability at elevated temperatures, was evaluated. In the first part of the work, microscopic research was carried out to determine the distribution of particle sizes in the cement suspension. Subsequently, five series of plate samples differing in the type of cement and the method of textile reinforcement saturation were designed and prepared. Mechanical experiments (four-point bending tests) were carried out to verify the properties of each sample type. It was found that the highest efficiency of carbon roving saturation was achieved by using finer ground cement (CEM 52.5) and the pressure saturation method. Moreover, this solution also exhibited the best results in the four-point bending test. Finally, the use of CEM 52.5 in the cement matrix appears to be a feasible variant for TRC constructions that could overcome problems with its low temperature resistance.

2016 ◽  
Vol 827 ◽  
pp. 227-230
Author(s):  
Ondřej Holčapek

Presented contribution deals with using textile reinforced concrete containing newly invented high strength cement matrix for strengthening concrete structures. The issue of old concrete ́s surface interaction with newly applied slim layer of textile reinforced concrete is investigated and verified by bending test. Water to binder ration under 0.3, maximum size of used silica sand 1.2 mm, and compressive strength over 100 MPa characterize used fine grain cement matrix. Over 12 months old beams with dimension 100 x 100 x 400 mm made from ordinary concrete were used for strengthening during performed experimental program. Strengthening took place on bending side. Different number (1, 3 and 5) of textile fabrics made from alkali-resistant glass (surface density 275 g/m2) was applied into slim layer of cement composite. Increasing number of used fabrics leads to different failure mode due shearing force action.


2014 ◽  
Vol 1054 ◽  
pp. 99-103 ◽  
Author(s):  
Filip Vogel ◽  
Ondřej Holčapek ◽  
Petr Konvalinka

This article deals with cement matrix for textile reinforced concrete. The main topic of this article is study of the development of the mechanical properties of the cement matrix. It was studied cube compressive strength and tensile strength in bending. The cement matrix has a similar composition as high performance concrete. Commonly used concrete was made to compare with the cement matrix. The cubes and prisms were made for the experimental program. The mechanical properties were studied at the age 12, 15, 18 and 21 hours and 1, 2, 3, 7, 14, 21 and 28 days.


2020 ◽  
Vol 309 ◽  
pp. 57-61
Author(s):  
Jakub Řepka ◽  
Tomáš Vlach ◽  
Diana Mariaková ◽  
Zuzana Jirkalová ◽  
Petr Hájek

This paper discusses the feasibility of an innovative anchoring element which is designed to be integrated into the volume of an ultra-thin coffered façade panel made of textile reinforced concrete and to not increase its external dimensions. The first part of the article describes the composition and shape of the façade panel and focuses on the manufacturing of the composite anchoring element made of carbon technical textile penetrated with polymer matrix which is intentionally identical composition as in the case of the façade panel reinforcement. The second part of the article focuses on the behavior of the composite anchoring element and its effect on its surroundings during the mechanical loading of the façade panel. Specimens of the coffered façade panel with integrated anchoring elements were subjected to four-point bending test to determine the impact of the anchoring elements on the façade panel flexural tensile strength and type of failure. Additional specimens were tested to determine the load-bearing capacity of the anchoring elements.


2016 ◽  
Vol 825 ◽  
pp. 7-10 ◽  
Author(s):  
Ondřej Holčapek ◽  
Filip Vogel

This paper deals with advanced application of textile reinforced concrete for strengthening and stabilization of existing load-bearing structure elements. Slim layer of fine grain concrete with compressive strength over 100 MPa was applied on one year old concrete beams with dimension 100 x 100 x 400 mm. Different number of layers of two types of textile fabrics was applied into concrete layer. One textile fabric was made from alkali-resistant glass fabric with surface density 585 g/m2 and the second was made from basalt fabric with surface density 260 g/m2. One layer of basalt textile fabric (surface density 120 g/m2) was applied on the top of strengthening layer to prevent shrinkage cracks of high strength cement matrix. Evaluation of destructive four points bending test of strengthened and reference specimens provided the efficiency of performed strengthening solution. Continual load and deflection measurement during bending test enables to create load-deflection diagram, where the action of textile can be observed.


2017 ◽  
Vol 259 ◽  
pp. 238-243 ◽  
Author(s):  
Jakub Řepka ◽  
Tomáš Vlach ◽  
Lenka Laiblová ◽  
Petr Hájek ◽  
Michal Ženíšek ◽  
...  

Use of high performance concrete with reinforcement made of technical textile is increasing and new applications are being found. This paper presents new technology for the lightening of the panels made of textile reinforced concrete, which is being developed. The main focus of this research is to produce concrete elements suitable for use as facade panels with the least possible weight and environmental impact. Mechanical characteristics were measured on testing specimens with thickness of 18 mm with lightening representing 47% of their volume. Minimum thickness of concrete was 4 mm and therefore the reinforcement was covered by approximately 1.5 mm of concrete matrix. The strength of experimental test panels was measured in four-point bending stress test. Due to one-sided lightening and asymmetrical cross-section therefore, the tests were performed in both directions. For better interpretation of the results were the specimens of lightened panels tested alongside non-lightened specimens with the same thickness. Based on measured values, maximal dimensions of lightened facade panels were designed.


2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.


2012 ◽  
Vol 510-511 ◽  
pp. 577-584 ◽  
Author(s):  
A. Quddos ◽  
Mohammad Bilal Khan ◽  
R.N. Khan ◽  
M.K.K. Ghauri

The impregnation of the fiber with a resin system, the polymeric matrix with the interface needs to be properly cured so that the dimensional stability of the matrix and the composite is ensured. A modified epoxy resin matrix was obtained with a reactive toughening agent and anhydride as a curing agent. The mechanical properties of the modified epoxy matrix and its fiber reinforced composites were investigated systematically. The polymeric matrix possessed many good properties, including high strength, high elongation at break, low viscosity, long pot life at room temperature, and good water resistance. The special attentions are given to the matrix due to its low out gassing, low water absorption and radiation resistance. In addition, the fiber-reinforced composites showed a high strength conversion ratio of the fiber and good fatigue resistance. The dynamic and static of the composite material were studied by thermo gravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) with EDX. The influences of processing technique such as curing and proper mixing on the mechanical and interfacial properties were determined. The results demonstrated that the modified epoxy resin matrix is very suitable for applications in products fabricated with fiber-reinforced composites.


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